In recent years, in order to protect the environment and improve fuel consumption of automobiles, there has been proposed an automobile designed to automatically stop the engine when the automobile stops, for example, so as to wait for a traffic light to change.
Incidentally, an ordinary car air conditioner has a problem in that, when an engine of an automobile in which the air conditioner is mounted is stopped, a compressor driven by the engine is stopped, and supply of refrigerant to an evaporator stops, whereby the cooling capacity of the air conditioner sharply drops.
As one measure to solve such a problem, imparting a cool storage function to the evaporator has been considered, to thereby enable cooling of a vehicle compartment by making use of cool stored in the evaporator, when the compressor stops as a result of stoppage of the engine.
An evaporator having a cool storage function has been proposed (see Patent Document 1). The proposed evaporator includes a plurality of flat refrigerant flow tube sections disposed in parallel such that their width direction coincides with an air flow direction, and they are spaced from one another; and hollow cool storage material containers each of which is fixedly provided on one side of a corresponding refrigerant flow tube section and contains a cool storage material therein. A plurality of sets each composed of a refrigerant flow tube section and a cool storage material container are provided at predetermined intervals along the longitudinal direction of header sections. Fins are disposed between adjacent sets each composed of a refrigerant flow tube section and a cool storage material container.
According to the evaporator having a cool storage function disclosed in Patent Document 1, a low temperature refrigerant flowing through the refrigerant flow tube sections enables storage of cool in the cool storage material within the cool storage material containers.
However, the evaporator having a cool storage function disclosed in Patent Document has a problem in that, when the effective core area is maintained constant, the number of the refrigerant flow tube sections decreases as compared with an ordinary evaporator having no cool storage material container, whereby cooling performance drops.